Abstract: A camera includes an electrically conductive housing defined by exterior walls and an interior cavity. The exterior walls of the housing have a lens opening and a connector opening formed therein. An imaging device is disposed within the interior cavity of the housing and communicates with the lens opening. A printed wiring board (PWB) is disposed within the interior cavity of the housing separating the imaging device from the connector opening. The PWB has an electrically conductive chassis plane operatively connected to the exterior walls of the housing so that the chassis plane and the housing form at least a partial Faraday cage around the imaging device.

Abstract: A camera includes an electrically conductive housing defined by exterior walls and an interior cavity. The exterior walls of the housing have a lens opening and a connector opening formed therein. An imaging device is disposed within the interior cavity of the housing and communicates with the lens opening. A printed wiring board (PWB) is disposed within the interior cavity of the housing separating the imaging device from the connector opening. The PWB has an electrically conductive chassis plane operatively connected to the exterior walls of the housing so that the chassis plane and the housing form at least a partial Faraday cage around the imaging device.

Abstract: A built-in test system for an ultrasonic liquid level sensor that includes a transducer assembly having an ultrasonic transducer, and a switch that will be actuated when the ultrasonic transducer is in intimate contact with a surface of a tank in which level is to be determined. Once the switch is actuated to indicate that the ultrasonic transducer is properly coupled to the surface, a test sequence is initiated to determine that the level of ultrasonic transmissions are above a certain desired threshold for a selected period of time, and after which the circuit looks for echoes to determine the depth of the liquid in the tank. Thereafter, the test sequence is repeated for each cycle of level sensing.

Abstract: A liquid level sensor used for determining liquid levels in a sealed container includes a heat source bonded to the container, a first temperature sensor mounted on the container adjacent the heat source, and a second temperature sensor mounted on the container spaced from the heat source. The temperatures at the first and second temperature sensors are sensed while the heat source is operating, and the differential in the temperatures is measured and used to control power to the heater. Changes in the differential in temperature between the first and second temperature sensors indicates when the heat conductivity between the first and second temperature sensors changes, due to presence or absence of a liquid in the container at the level of the temperature sensors.

Abstract: A liquid level sensor is used on a sealed container comprises a heat source bonded to the container, a first temperature sensor mounted on the container adjacent the heat source, and a second temperature sensor mounted on the container spaced from the heat source. The temperatures at the first and second temperature sensors are sensed while the heat source is operating, and the differential in the temperatures is measured and used to control power to the heater. Changes in the differential in temperature between the first and second temperature sensors indicates when the heat conductivity between the first and second temperature sensors changes, due to presence or absence of a liquid in the container at the level of the temperature sensors.

Abstract: A built-in test system for an ultrasonic liquid level sensor that includes a transducer assembly having an ultrasonic transducer, and a switch that will be actuated when the ultrasonic transducer is in intimate contact with a surface of a tank in which level is to be determined. Once the switch is actuated to indicate that the ultrasonic transducer is properly coupled to the surface, a test sequence is initiated to determine that the level of ultrasonic transmissions are above a certain desired threshold for a selected period of time, and after which the circuit looks for echoes to determine the depth of the liquid in the tank. Thereafter, the test sequence is repeated for each cycle of level sensing.

Abstract: A sensor for measuring the height of fluid in a vessel, the sensor including a mounting base shaped to be coupled to an exterior surface of a vessel. The sensor further includes a transducer having a pulse source for sending pulses into the vessel and an echo detector for detecting echoes of pulses emitted by the pulse source. The sensor further has a dry couplant located between the transducer and the mounting base, and a processor connected to the transducer for calculating the height of fluid in the vessel based at least in part upon the time elapsed between the pulses sent by the transducer and echoes detected by the echo detector.

Abstract: An air data module connector and filter that provides a shielded housing 12 for supporting a standard air data signal carrying cable connector 22 on an exterior wall thereof, and having an access opening that has a cover plate 34 on an opposite wall from the mounting wall for the connector. The cover plate 34 has a plurality of tubular filters 36 installed therein with pins 40 extending into the housing toward the cable connector. A flexible circuit board 44 has opposite ends which fit on the pins of the connector 23, and the pins 40 of the filters 36 extending through the cover plate, respectively, so that the flexible circuit board 44 can be installed on the cable connector 23 and on the pins 40 for the filters on the cover plate 34 prior to assembly of the cable connector and the cover plate 34 in the housing 12.

Abstract: A strain gage pressure sensor having a resistive bridge circuit from which is measured both the applied pressure and the temperature of the pressure sensor. A constant voltage is provided across the bridge circuit such that any temperature caused changes in the resistance of the bridge circuit are reflected in the flow of a bridge current through the bridge circuit. A sense resistor is electrically coupled to the bridge circuit such that any change in the bridge current causes a change in the voltage drop across the sense resistor. The voltage drop and the pressure output signal are digitized and suitably processed resulting in a highly accurate, corrected pressure output for use with suitable pressure instrumentation.